With the improvement of integrated circuit (IC), the application of an MCU chip becomes more widely used from toys to construction machinery. An MCU chip usually comprises a central processing unit (CPU), a flash, a static random access memory (SRAM) and a variety of peripherals. When the MCU chip is power down, flash content is not lost, while SRAM content is. A flash memory is usually composed of two distinct areas: one is a user area, used to store user's program, the other is an information area, used to store configuration information of the MCU chip. SRAM is usually used as an on-chip memory.
For an MCU application solution provider, a manufacturer who develops program and PCB (printed circuit board) based on the MCU chip, the program will be recorded on the user area of a flash memory. The core value of the application solution provider is the program. Thus, the program should be protected from being stolen by others. The information protection method of an MCU chip is to protect the program stored in the user area of a flash memory from being stolen by others. The current information protection method for an MCU chip is only available to protect the program in the user area as a whole, but not able to protect a program developed by two or more cooperative companies. Because the current method can only be used to protect the program in the user area from being stolen by users, not be used to prevent the cooperative companies stealing the program from each other.
Therefore, an urgent technical problem to be solved for the technicians in this field is: providing an information protection method for an MCU chip to protect the program from being stolen by users and prevent the companies who developed the program together stealing program from each other.